.TH std::isgraph 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::isgraph \- std::isgraph

.SH Synopsis
   Defined in header <cctype>
   int isgraph( int ch );

   Checks if the given character is graphic (has a graphical representation) as
   classified by the currently installed C locale. In the default C locale, the
   following characters are graphic:

     * digits (0123456789)
     * uppercase letters (ABCDEFGHIJKLMNOPQRSTUVWXYZ)
     * lowercase letters (abcdefghijklmnopqrstuvwxyz)
     * punctuation characters (!"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~)

   The behavior is undefined if the value of ch is not representable as unsigned char
   and is not equal to EOF.

.SH Parameters

   ch - character to classify

.SH Return value

   Non-zero value if the character has a graphical representation character, zero
   otherwise.

.SH Notes

   Like all other functions from <cctype>, the behavior of std::isgraph is undefined if
   the argument's value is neither representable as unsigned char nor equal to EOF. To
   use these functions safely with plain chars (or signed chars), the argument should
   first be converted to unsigned char:

 bool my_isgraph(char ch)
 {
     return std::isgraph(static_cast<unsigned char>(ch));
 }

   Similarly, they should not be directly used with standard algorithms when the
   iterator's value type is char or signed char. Instead, convert the value to unsigned
   char first:

 int count_graphs(const std::string& s)
 {
     return std::count_if(s.begin(), s.end(),
                       // static_cast<int(*)(int)>(std::isgraph)         // wrong
                       // [](int c){ return std::isgraph(c); }           // wrong
                       // [](char c){ return std::isgraph(c); }          // wrong
                          [](unsigned char c){ return std::isgraph(c); } // correct
                         );
 }

.SH Example


// Run this code

 #include <cctype>
 #include <clocale>
 #include <iostream>

 int main()
 {
     unsigned char c = '\\xb6'; // the character ¶ in ISO-8859-1

     std::cout << "isgraph(\\'\\\\xb6\\', default C locale) returned "
               << std::boolalpha << (bool)std::isgraph(c) << '\\n';

     std::setlocale(LC_ALL, "en_GB.iso88591");
     std::cout << "isgraph(\\'\\\\xb6\\', ISO-8859-1 locale) returned "
               << std::boolalpha << (bool)std::isgraph(c) << '\\n';
 }

.SH Possible output:

 isgraph('\\xb6', default C locale) returned false
 isgraph('\\xb6', ISO-8859-1 locale) returned true

.SH See also

   isgraph(std::locale) checks if a character is classified as graphical by a locale
                        \fI(function template)\fP
   iswgraph             checks if a wide character is a graphical character
                        \fI(function)\fP
   C documentation for
   isgraph

        ASCII values            characters    iscntrl  isprint  isspace  isblank  isgraph  ispunct  isalnum  isalpha  isupper  islower  isdigit  isxdigit
decimal hexadecimal   octal                   iswcntrl iswprint iswspace iswblank iswgraph iswpunct iswalnum iswalpha iswupper iswlower iswdigit iswxdigit
0–8     \\x0–\\x8     \\0–\\10    control codes   ≠0       0        0        0        0        0        0        0        0        0        0        0
                              (NUL, etc.)
9       \\x9         \\11       tab (\\t)        ≠0       0        ≠0       ≠0       0        0        0        0        0        0        0        0
                              whitespaces
10–13   \\xA–\\xD     \\12–\\15   (\\n, \\v, \\f,    ≠0       0        ≠0       0        0        0        0        0        0        0        0        0
                              \\r)
14–31   \\xE–\\x1F    \\16–\\37   control codes   ≠0       0        0        0        0        0        0        0        0        0        0        0
32      \\x20        \\40       space           0        ≠0       ≠0       ≠0       0        0        0        0        0        0        0        0
33–47   \\x21–\\x2F   \\41–\\57   !"#$%&'()*+,-./ 0        ≠0       0        0        ≠0       ≠0       0        0        0        0        0        0
48–57   \\x30–\\x39   \\60–\\71   0123456789      0        ≠0       0        0        ≠0       0        ≠0       0        0        0        ≠0       ≠0
58–64   \\x3A–\\x40   \\72–\\100  :;<=>?@         0        ≠0       0        0        ≠0       ≠0       0        0        0        0        0        0
65–70   \\x41–\\x46   \\101–\\106 ABCDEF          0        ≠0       0        0        ≠0       0        ≠0       ≠0       ≠0       0        0        ≠0
71–90   \\x47–\\x5A   \\107–\\132 GHIJKLMNOP      0        ≠0       0        0        ≠0       0        ≠0       ≠0       ≠0       0        0        0
                              QRSTUVWXYZ
91–96   \\x5B–\\x60   \\133–\\140 [\\]^_`          0        ≠0       0        0        ≠0       ≠0       0        0        0        0        0        0
97–102  \\x61–\\x66   \\141–\\146 abcdef          0        ≠0       0        0        ≠0       0        ≠0       ≠0       0        ≠0       0        ≠0
103–122 \\x67–\\x7A   \\147–\\172 ghijklmnop      0        ≠0       0        0        ≠0       0        ≠0       ≠0       0        ≠0       0        0
                              qrstuvwxyz
123–126 \\x7B–\\x7E   \\172–\\176 {|}~            0        ≠0       0        0        ≠0       ≠0       0        0        0        0        0        0
127     \\x7F        \\177      backspace       ≠0       0        0        0        0        0        0        0        0        0        0        0
                              character (DEL)
